My father -in-law left us a couple of HO brass engines that were stored in the original boxes for many years. When opened the foam had completely encased the engine and stuck to it. So far I have tried Goo, light isopropyl alcohol and vinegar for cleaning the brass when I get to it. but the brass seems to have a mottled effect now - even after many hours of cleaning. Any suggestions, if possible, to return engine to original surface shine and color, from here?
Maybe a metal polish such as for mag wheels, which you can get at any automotive supply place.
Unpainted brass locomotives usually come from the factory with a protective coating, so your mottled appearance may be caused by partial removal of the lacquer.
Probably the easiest way to get rid of the foam is to disassemble the loco (make notes and diagrams to assist in getting it back together), then place it in hot water and dish detergent and let it soak. Don't, of course, get the motor wet at all, and don't immerse the drivers for too long, as the insulation between the wheels and tires is usually a paper product. If necessary, use a soft brush (toothbrush or scrub brush) to remove any stubborn bits.
As for the mottled appearance, it's unlikely that your cleaning methods have removed the finish, which was usually lacquer-based, either clear or, more often, brass-coloured paint. There's a chance that they were never painted or that the original finish was, for some reason, already stripped.
Wayne
You could also try removing any and all plastic and soaking the brass parts in lacquer thinner. Lacquer thinner melts plastic very quickly, so it should take care of the foam without damaging the brass. I like using this stuff for stripping paint off metal and brass, because it works quickly and doesn't damage the metal.
I got a brass diesel a while back with some stuck foam. I decided to use a fine steel wire wheel instead, because I was going to paint the whole engine anyway. It took the foam right off, and the paint covered all of the microscopic scratches left by the wire wheel.
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What you need is something that will break down the foam bits, but not damage the brass.
I would have thought GOO GONE would have worked...it is designed to break down adhesives right? or am I thinking of the worng stuff?
Taking it apart and soaking my be your only best bet. A lite tooth-brushing maybe needed.
I wonder...you tried alcohol, but I wonder if somehting as crazy as Witch Hazel might work to rub it off and leave the finish in fine shape? {Witch hazel is in the pharmacy wiht the rubbing alcohol and bandaids and stuff. It's amazing what it can do as an astringent that doesn't burn like alcohol.}
Just an Idea.
This is why one should wrap tissue around a loco before puttting back into foam, or in storage.
-G .
Just my thoughts, ideas, opinions and experiences. Others may vary.
HO and N Scale.
After long and careful thought, they have convinced me. I have come to the conclusion that they are right. The aliens did it.
Foam is a plastic, so it's a chemical bond from a reaction to the metal as the foam breaks down rather than an adhesive bond. It takes an oil solvent like enamel thinner or lacquer thinner to dissolve the foam. Thinners won't damage the metal (they usually come in metal cans).